Air seat suspension systems are expected to respond to relatively high amounts of often sudden and sometimes erratic forces. The needs of the system frequently change, depending upon key variables, such as driver weight and the vehicle load. The environmental conditions inside a cab of a parked vehicle can vary dramatically over a short time, with temperature changes of 100 degrees F. in under an hour. Some prior art systems are too costly for widespread deployment.
Consequently, there is a need for a low cost, rugged, adjustable, three-state, bi-directional flow control device.